Why is Regeneron Pharmaceuticals facing a securities class action lawsuit?

Investors allege Regeneron made misleading statements about the Phase III Fianlimab-Libtayo clinical trial and its likelihood of success.

What are investors claiming about Regeneron’s Phase III trial?

The complaint alleges the trial relied on flawed statistical assumptions and was unlikely to achieve its primary endpoint.

What is the Fianlimab-Libtayo study?

Fianlimab-Libtayo is a Phase III clinical trial evaluating an investigational cancer treatment combination developed by Regeneron.

Why are statistical assumptions important in the Regeneron lawsuit?

Clinical trial design depends on statistical assumptions to measure success. Investors allege those assumptions were fundamentally flawed.

What is a primary endpoint in a clinical trial?

A primary endpoint is the main outcome a study must achieve to demonstrate a treatment's effectiveness.

What are investors alleging about the treatment's effectiveness?

The complaint claims the treatment failed to meaningfully outperform existing standard therapies.

Why is clinical differentiation important in the Regeneron case?

Clinical differentiation helps show a new treatment offers meaningful benefits over existing therapies.

What are investors alleging Regeneron failed to disclose?

Plaintiffs claim the company failed to disclose risks that the trial would not achieve statistical significance.

How can unsuccessful clinical trials affect a biotechnology company?

Failed trials may delay approvals, reduce future revenue opportunities, and negatively affect investor confidence.

Who may qualify to participate in the Regeneron class action?

Investors who purchased Regeneron Pharmaceuticals (NASDAQ: REGN) securities between August 1, 2025 and May 15, 2026 may be eligible if they suffered losses.

What is the deadline to seek lead plaintiff status in the Regeneron lawsuit?

Investors seeking appointment as lead plaintiff must file a motion by September 14, 2026.

What is a securities class action lawsuit?

A securities class action allows investors to collectively pursue claims against a company for alleged misleading statements or omissions.

What does the term “class period” mean in a securities lawsuit?

The class period is the timeframe during which alleged misleading statements occurred and investors may have purchased securities.

What is a lead plaintiff in a securities class action?

The lead plaintiff is the investor selected by the court to represent the interests of all class members throughout the litigation.

How do investors receive compensation from a securities class action settlement?

If a settlement is reached, eligible investors may submit claim forms documenting qualifying transactions to receive a share of the settlement fund.

Regeneron Pharmaceuticals, Inc. - Faruqi & Faruqi LLP

Regeneron Pharmaceuticals, Inc.

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Case Details

Ticker REGN

Class Period 08/01/2025 - 05/15/2026

Lead Plaintiff Deadline 09/14/2026

Days Left to Seek Lead Plaintiff

If you are a Regeneron Pharmaceuticals investor who suffered a loss and would like to learn more, you can provide your information below:

Faruqi & Faruqi, LLP Securities Litigation Partner James (Josh) Wilson Encourages Investors Who Suffered Losses In Regeneron To Contact Him Directly To Discuss Their Options

If you purchased or acquired securities in Regeneron between August 1, 2025 and May 15, 2026 and would like to discuss your legal rights, call Faruqi & Faruqi partner Josh Wilson directly at 877-247-4292 or 212-983-9330 (Ext. 1310).

Faruqi & Faruqi, LLP, a leading national securities law firm, is investigating potential claims against Regeneron Pharmaceuticals, Inc. (““Regeneron” or the “Company”) (NASDAQ: REGN) and reminds investors of the September 14, 2026 deadline to seek the role of lead plaintiff in a federal securities class action that has been filed against the Company.

As detailed below, the complaint alleges that the Company and its executives violated federal securities laws by making false and/or misleading statements and/or failing to disclose the true state of Regeneron’s Phase III Fianlimab-Libtayo Study; notably, that its preliminary statistical assumptions were fundamentally flawed, that the active treatment arm was failing to achieve meaningful clinical differentiation over standard therapies, and that the trial would ultimately fail to reach statistical significance on its primary endpoint even without overperformance of the control arm.

Lead Plaintiff Deadline: September 14, 2026

Call Partner Josh Wilson at 877-247-4292 or 212-983-9330 (Ext. 1310)
Or submit your information below to learn about your rights.

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